How do you judge the quality of a pitch?
Not by velocity alone. Yankees right-hander Nathan Eovaldi owns the second-fastest fastball among starting pitchers this year, yet his fastball wouldn't make anyone's top-five list. And Royals starter Yordano Ventura has been struggling quite a lot for a guy with easy 95 mph cheese.
Not by movement alone, either. Rangers lefty Martin Perez has a sinker in the top five in horizontal movement, Mariners veteran Hisashi Iwakuma has a show-me curve he sometimes breaks out that has top-10 horizontal movement, and Joe Ross' changeup has top-five horizontal movement for a right-handed change (though he rarely throws it).